On the desk____a book and two pens.横线里填is 还是are?

On the desk____a book and two pens.横线里填is 还是are? There( are )(a book)and (two pens)(on) the desk There are a book and two pens on the desk . There is a book and two pens on the desk. 连词成句：there,a,book,and,pens,two,are,desk,the,on(.) There __ a book and two pens on the desk.答案是is.为什么 There is a book and two pens on the desk.这句话是不是错了? there were a book and two pens on the desk There a book and two pens on the desk. where___the book and the pen?横线上填is还是are? There ___a desk and two beds in the room.横线上填is还是are? There are a pencil and two pens on the desk.